Large Amplitude Oscillatory Shear of Block Copolymer Spheres on a Body-Centered Cubic Lattice: Are Micelles Like Metals?
- UMM
Small-angle X-ray diffraction experiments have uncovered a remarkable mechanism of grain alignment during plastic deformation of ordered sphere-forming diblock copolymer micelles when subjected to large amplitude dynamic shearing. A nearly monodisperse poly(styrene-b-ethylene-alt-propylene) (SEP) diblock copolymer with block molecular weights of 42,000 and 60,000 was mixed with squalane (C{sub 30}H{sub 62}), an EP selective solvent, at a concentration of 10 wt %. After high temperature annealing, the sample formed an ordered polydomain morphology containing glassy S cores at room temperature. SAXS powder patterns confirm body-centered cubic (BCC) symmetry and reveal the development of a complex array of two-dimensionally resolved Bragg reflections following the application, and cessation, of oscillatory shearing. These diffraction results are interpreted on the basis of the classic mechanism of crystalline slip, which accounts for plastic deformation of ductile materials such as metals. Four distinct slip systems are shown to be active in this work, suggesting a robust basis for deforming and mixing of soft ordered solids.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
- Sponsoring Organization:
- NSFUNIVERSITY
- OSTI ID:
- 1049558
- Journal Information:
- J. Phys. Chem. B, Vol. 115, Issue (19) ; 05, 2011; ISSN 1520-6106
- Country of Publication:
- United States
- Language:
- ENGLISH
Similar Records
Addition of Corona Block Homopolymer Retards Chain Exchange in Solutions of Block Copolymer Micelles
Effect of Corona Block Length on the Structure and Chain Exchange Kinetics of Block Copolymer Micelles